Imiquimod (INN) is a prescription medication that acts as an immune response modifier. It is marketed by MEDA AB, Graceway Pharmaceuticals and iNova Pharmaceuticals under the trade name Aldara and by Mochida as Beselna.

Uses

Imiquimod is a patient-applied cream used to treat certain diseases of the skin, including skin cancers (basal cell carcinoma, Bowen's disease, superficial squamous cell carcinoma, some superficial malignant melanomas, and actinic keratosis) as well as genital warts (Condylomata acuminata). It has also been tested for treatment of Molluscum contagiosum, VIN (Vulvar intraepithelial neoplasia) and VAIN (vaginal intraepithelial neoplasia).

History

The original FDA approval was on February 27, 1997, FDA Application No. (NDA) 020723, by Graceway.

Since then, the label has been revised many times. Adverse side effects have been reported, in some cases serious and systemic.

Mechanism of action

The exact mechanism of action in which imiquimod and its analogs activate the immune system is not yet known. Nevertheless, it is known that imiquimod activates immune cells by ligating the toll-like receptor 7 (TLR7), commonly involved in pathogen recognition, on the cell surface. Cells activated by imiquimod via TLR-7 secrete cytokines (primarily interferon-α (IFN-α), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α)). There is evidence that imiquimod, when applied to skin, can lead to the activation of Langerhans cells, which subsequently migrates to local lymph nodes to activate the adaptive immune system. Other cell types activated by imiquimod include natural killer cells, macrophages and B-lymphocytes.

New research has shown that imiquimod's anti-proliferative effect is totally independent of immune system activation or function. Imiquimod exerts its effect by increasing levels of the opioid growth factor receptor (OGFr). Blocking OGFr function with siRNA technology resulted in loss of any antiproliferative effect of imiquimod.

References

External links

• NPS RADAR
• Aldara.com